Extraction of high purity amorphous silica from rice husk by chemical process

Abstract

Abstract High purity amorphous silica (SiO2) is extracted from agriculture waste (rice husk) that supplied from Al-Najaf province, Iraq. Silica is the major inorganic constituent of the rice husk. It is prepared with using acid pretreatment of (3N HCl), then burned it at (700°C) for 4 hrs, and followed with leaching process by 1.5, 2, 2.5, and 3N NaOH. The extracted results are high-surface area of amorphous silica particles. Extracted results are silica particles were high surface area of amorphous silica particles. These particles were characterized by X-Ray diffraction (XRD), and X-Ray Fluorescence (XRF) and Atomic force microscopy (AFM) techniques. High pure amorphous silica observed from rice husk ash was confirmed by XRD diffraction. The silica purity results measured by X-Ray fluorescence was 99.714% for leaching at 3N NaOH. Results from (AFM) of silica with nanoscale sizes and microparticles with diameters ranging from (87-114) nm.